The present invention relates to a buffing machine for lens, and in particular to a buffing machine for lens used to polish end surfaces of lenses of eyeglasses.
Among eyeglasses currently in practical use, frameless eyeglasses have no frame to accommodate lenses and the eyeglasses are used with end surfaces of the lenses exposed to outside. In this respect, end surfaces of the lenses are polished by buffing to finish them as mirror surfaces.
Now, description will be given on a conventional type buffing machine for lens, referring to FIG. 11 and FIG. 12.
In the figure, reference numeral 1 represents a lens of eyeglasses, and the lens 1 of eyeglasses is held by lens chuck shafts 2 of the buffing machine for lens and 2 via lens chucks 3 and 3, and there is provided a buff wheel 4, which has a rotation axis in parallel to an axis of the lens chuck shaft 2. The buff wheel 4 is produced by sewing a buff cloth 5 together. The lens chuck shaft 2 is rotatably mounted on a tiltable frame (not shown) and is rotated by a motor (not shown) installed on the frame.
In case end surface of the lens 1 of eyeglasses is to be buffed, it is chucked by the lens chuck shafts 2 and 2. Then, the frame not shown in the figure is laid down, and the end surface of the lens 1 of eyeglasses is brought into contact with the rotating buff wheel 4 while the lens 1 of eyeglasses is being rotated.
In the buffing machine for lens as described above, the surface of the buff cloth 5 is fluffy. As seen in FIG. 12, fluffs 6 on the surface of the buff cloth 5 are raised perpendicularly with respect to the peripheral end surface of the buff wheel 4 due to centrifugal force caused by the rotation of the buff wheel 4. The front surface of the lens is usually curved toward +side (i.e. convex side), and the fluffs 6 buff or polish peripheral edges of front surface of the lens 1 of eyeglasses. Various types of coating 7 are coated on the lens to protect the lens body or to increase transmittance of light. There have been problems in that the coating 7 on peripheral edges of the lens is damaged by the fluffs 6. In the conventional type buffing machine, buff having high rigidity such as hard buff, felt buff, etc. has been used so that the end of the lens is not buried in the buff. Therefore, it is easy to buff end surface of the lens when end surface is flat, but if end surface is V-shaped, only tips of the end surface of the lens touch the surface of the buff, and it is difficult to buff the entire end surface of the lens.